Fuel is continuously drawn from the fuel tank by the internal combustion engine whereby an underpressure can build up above the surface of the fuel in the tank. This underpressure can retard the outflow of the fuel to the engine. An underpressure which builds up in the tank can lead to a quantity of fuel which is so greatly reduced that operational disturbances can occur in the internal combustion engine supplied by the fuel-fed carburetor.
It is known to provide a venting valve or the like for a fuel tank to compensate for the pressure. The venting valve opens when the underpressure exceeds an underpressure limit value so that the underpressure can be reduced by inflowing ambient air. However, it has been shown that dirt particles entrained in the ambient air can lead to a non-tight seating of the valve body on the valve seat. Fuel can leak from the venting valve when the work apparatus is held in certain work positions. This condition not only presents a considerable burden to the operator but also carries with it the danger of fire which should not be underestimated and which can place the operator in considerable danger.